Testing ad block visibility
To provide partners and advertisers with objective statistics, the Yandex Advertising Network counts only impressions of those blocks that were seen by website users and app users. An ad block impression counts if at least 50% of the block area is in the visible area of the screen for at least two seconds.
The reasons why website users did not see advertisements on the site could be as follows:
The ad is displayed beyond the visible part of the site: for example, when ads are positioned at the end of the page or in a part of the page that is not seen on the screen without scrolling.
The ad code does not load the ad quickly enough before the user leaves the page: for example, when a page contains a large number of elements like pictures, videos, large tables, etc. This problem occurs most often for users with a slow internet connection.
In this case, you can use the asynchronous ad call code RTB ad blocks to load pages and the ad code simultaneously.
There could be a conflict between ad code and other scripts running on the page: in this case, you can run a script check and find out which of them is affecting the Yandex ad display. One by one, disable all scripts that run on the page in order to identify the one that is causing the conflict.